GCI--Ground or Ship Control of Interception Sets

SCR-588 Long Wave Aircraft detector and GCI

To give continuous plan position and accurate relative height of
enemy plane and friendly fighter plane for GCI. Set can also be
used for early warning and to give increased coverage at low
angles of search. IFF equipment RC-188 is used. When operating
as GCI, VHF equipment SCR-624 is required.

PERFORMANCEAND SITING:

Maximum range on a medium bomber, with set on flat sea level site:

Altitude, feet

1000

5000

10,000

25,000

Range*, miles

20

50

95

105

*Range of PPI limits GCI operation to about 45 miles.

When operating as GCI, set must be sited so that a flat unobstructed
surface extends at least 1/4th mile in the
height-finding sector. Good GCI sites are extremely rare. For early warning,
sets should be sited between 100 and 1,000 feet above an unobstructed surface.

TRANSPORTABILITY:

Set is packaged for shipment in 55 units, weighing a total of
54,000 lbs. Largest unit measures 15.3' x 3.8' x 1.8'. Total
shipping space is 3500 cu. ft.

INSTALLATION:

Requires a weatherproof building approximately 20' x 40' for housing
radar components and a building approximately 20' x 20' for
power units and switchboard. A 25' tower on concrete footing is
required for support of antenna. Buildings and tower can be
built by Engineers in about 3 weeks. Radar can be installed by 5
men in 2 weeks.

PERSONNEL:

8 men are operating crew. For 24-hour operation about 54 men are
required to run radar, communication radio, and camp.

SCR-527 Mobile Long Wave Aircraft detector and GCI

To provide necessary continuous plan position and accurate relative
height of enemy plane and friendly fighter plane for GCI.
Set can also be used for early warning and to give increased coverage
at low angles of search. IFF equipment RC-127 is used.
When operating as a GCI station, VHF equipment SCR-624 is required.

PERFORMANCEAND SITING:

Maximum range on a single medium bomber flying at indicated altitudes
when set is installed on a flat sea level site:

Maximum range on a medium bomber, with set on flat sea level site:

Altitude, feet

1000

5000

10,000

25,000

Range*, miles

17

35

90

100

*Range of PPI limits GCI operation to about 45 miles.

When operating as GCI, set must be sited so that a flat unobstructed
reflecting surface extends at least 1/4th mile in the sector
in which height-finding is desired. Good GCI sites are extremely
rare, and workable sits are found only with difficulty.
When used for early warning, these sets should be sited at a
height between 100 and 1,000 feet above an unobstructed reflecting surface.

INSTALLATION:

Operates from trucks in which mounted. Can be placed in operation
in approximately 6 hours after arrival at proper site.

TRANSPORTABILITY:

Set consists of 7 vehicles weighing a total of 97,610 lbs.
Largest vehicle measures 26'21/2" x 8'11/2" x 10'.

PERSONNEL:

8 men are operating crew. For 24-hour operations, about 54 men
are required for operation of radar, communication radio, and camp.

POWER:

Supplied by two PE 137-A 25 KW, 120/208 V gasoline generators, one
of which serves as a spare. Supplied with set in separate trucks.
Fuel consumption is 2.4 gal. per hour of non-leaded standard commercial gasoline.

SCR-615-A and SCR-615-B Microwave Aircraft Detectors for GCI

Adjunct to a search radar to give accurate height data, thus permitting
GCI operation from sites not suitable for other GCI sets
which need flat sites. Also gives low-angle coverage when operated
as search set. IFF equipment RC-215 is used.

PERFORMANCEAND SITING:

Range on a single, medium bomber flying at indicated altitudes:

Altitude, feet

1000

5000

10,000

25,000

615-A, range, Miles.

25

35

35

35

615-B, range, Miles.

25

50

50

50

For height finding, set is sited near search set so objects which
may cause ground clutter are screened from set by nearby hills.

For low angle early warning, set is sited as high as possible in
coastal areas overlooking sea. When sited overlooking land, the
site should be as high as possible. Back radiation is negligible.

TRANSPORTABILITY:

When packed for shipment by freight the total weight is expected
to be approximately 10,000 lbs.

INSTALLATION:

Antenna and transmitting and receiving components are installed on
a wooden tower 30', 55', or 105' high, depending on site. Operating
controls and presentation unit are installed in a separate
weatherproof building approximately 20' x 20'. If used as adjunct
to a search type set, controls and presentation can be installed
in same building with search set equipment. A 20' x 20' building
is required for power units and switchboard. Tower and buildings
must be built by engineers and require approx. 2 weeks. Radar
components can then be installed by 5 men in about 5 to 6 days.

PERSONNEL:

8 men comprise an operating crew. For 24-hour operation about 54
men are required to operate radar, communication radio and camp.

POWER:

12 KW, 120/208 V 3 phase supplied by electric diesel generator.

--54--

*SCR-627 Long wave GCI

SCR-627

DESCRIPTION:

Fixed, long wave medium-range GCI that supplies azimuth, altitude,
and range data on planes. Two PPI and one HR scope supplied.

USES:

To provide continuous plan position and accurate relative height
of enemy plane and friendly fighter plane for GCI. Set can also
be used for early warning and to give increased coverage at low
angles of search. IFF equipment RC-207 is used with this set.
When operating as a GCI station, VHF communication equipment
SCR-624 is required.

PERFORMANCEAND SITING:

Maximum range on a single medium bomber flying at indicated altitude,
when set is installed on a flat sea-level site:

Altitude, feet

1000

5000

10,000

25,000

Range*, miles

25

60

120

135

*Range of PPI limits GCI operation to approx. 45 mi.

When operating as GCI, set must be sited so that a flat unobstructed
reflecting surface extends at least 1/4 mile in the
sector in which height-finding is desired. For early warning,
set should be sited between 100 and 1000 feet above an unobstructed
reflecting surface.

TRANSPORTABILITY:

Set when crated is expected to weigh about 75,000 lbs.

INSTALLATION:

Requires a weatherproof building about 20' x 40' for housing radar
components, and a building 20' x 20' for the power units and
switchboard. Antenna structure is approximately 30' L x 30' H x
20' D and mounts on turning gear installed in a concrete pit approx.
11' x 11' x 7' D. Buildings and tower must be built by engineers
in about 3 weeks. Radar components can be installed by 5
men in about 3 or 4 days.

PERSONNEL:

8 men comprise an operating crew. For 24-hour operation about 54
men are required to run radar, communication radio, and camp.

*SM Microwave Shipborne CG Set

See also CIC Manual
for descriptions of radars integrated into Combat Information Centers, PPI,
IFF, etc.

SM on Aircraft Carrier

DESCRIPTION AND USES:

Microwave set with three axis stabilized antenna, installed on aircraft
carriers to search for enemy planes, particularly low-flying
and shadow planes, and to supply height, speed and course data so
that a Fighter Director Officer can direct fighters to an interception.
Can also be used to search for ships and periscopes. SM
is correlated with search sets, such as SK, and with radio communication
to planes. Has provisions for A and G band IFF, and a
built-in BO antenna. For night interception, AIA is required in planes.

PERFORMANCE:

SM has a reliable detection range of 35 miles on a medium bomber
500 ft. above optical horizon. surfaced submarines can be followed
to horizon. Periscopes can be seen 6 miles or more, and buoys can
be seen up to horizon. Range can be determined to ± 200 yds., or
1/4%, whichever is greater. Bearing can be determined
to ± 1/2°. Elevation
can be determined to ±1/3°
if airplane is 21/2° or more above
optical horizon. If plane is lower, data is less reliable. Accuracy
of range difference between two targets is ± 50 yds. for separation
of 500-10,000 yds. Elevation limit is 90°.

TRANSPORTABILITY:

Spares, testing equipment and separate generator supplied.

INSTALLATION:

SM has 23 components weighing a total of about 9 tons. Largest
unit is the antenna mount -- 131" high, with a diameter of 67" at
base, and weighing about 4,600 lbs. The antenna is 6 ft. in diameter;
8-foot antennas will be installed on later sets. The console
(76" x 65" x 24" -- 1,800-2,000 lbs.) splits into 3 parts for installation.